The copper diffusion barrier properties of layered silicate/fluorinated polyimide nanocomposites were analyzed by transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS). It was found that the particles of copper are effectively retarded from penetrating into the polyimide matrix by layered silicates. The diffusion coefficients of layered silicate/polyimide nanocomposites are lower than that of the pure polyimide. (C) 2004 Wiley Periodicals, Inc.